Thermal near-field radiation of artificial materials

Heat radiation emitted by a medium with a given temperature depends on its material properties, and on its geometry as well. Artificial materials such as nanoporous media, photonic crystals, meta-materials or hyperbolic media feature very unusual optical properties, because of the combined effect of the properties of the respective material itself and of its geometrical structure. For example, by drilling nanoscale holes into a SiC or Au slab, or by ruling a nanoscale grating onto a SiC or Au surface, one can change the optical properties dramatically. This change, in its turn, can enhance or inhibit the heat flow caused by thermal radiation between such media. Therefore, artificial materials allow one to taylor the heat flux. We are investigating not only how the heat flux at the nanoscale can be controlled by such structures, but we also try to give an answer to a much more fundamental question: How does a black body for nanoscale heat radiation look like? And is it possible to artifically manufacture a black body for near-field heat radiation?

transmission coefficient for nanoporous materials